E(level): From least-squares fit to γ energies where γ transitions occur; otherwise from average of results of reaction studies. For γ’s whose energies are quoted to only the nearest keV, the ΔE values are assumed to be 1 keV. For levels all of whose deexciting γ’s are known to only the nearest keV no uncertainties are given for the level energies.

J^π(level): Jπ and band assignments are based on the following: ce data from ¹⁶¹Er ε decay studies; γ(θ) from in-beam studies, especially as they imply stretched E2 character of the γ’s; the agreement of measured and calculated cross sections for the charged-particle reactions; and the expected structure of the rotational bands.

J^π(level): Wave functions from model calculations of 1992Bo45 show >88% of the state corresponds to the Nilsson state listed here for bandheads at 0, 211, 252, 298, 760, and 826 keV. The model results for the bandheads at 423, 446, and 592 keV are listed for those levels.

E(γ): From decay-scheme studies (primarily 1972Ka37 and 1972Wo08) and in-beam studies (primarily 1971Fu08 and 2004Es01). Unplaced γ’s from ¹⁶¹Er ε decay and in-beam studies are not included here. γ’s listed only to the nearest keV are generally from 2004Es01.

I(γ): Average of available data from decay scheme and in-beam studies.

M(γ): Multipolarities are based primarily on relative internal-conversion subshell intensities (1965Gr35) and α(K)exp values (1972Ka37) in ¹⁶¹Er ε decay, and γ(θ) from (α,2nγ) study (1971Fu08). The Q are generally taken to be stretched E2. See the ¹⁶¹Er ε decay and (α,2nγ) for the experimental results.